Method and device for transmitting information comprising a speech part and a data part

ABSTRACT

The invention relates to a method and a device in a communications system, for Internet protocol (IP)-based transmission of information comprising a speech part and a data part between interface units with a plurality of ports. The speech part and the data part are transmitted to separate ports of the receiving interface unit, the ports that are used being allocated to each other in the communications system as corresponding ports.

[0001] The invention relates to a method and a device for Internet Protocol (IP)-based transmission of information comprising a speech part and a data part in a communications system according to the pre-characterizing clause of claim 1.

[0002] As computers are integrated into communication services, IP-based transmission of information is also being increasingly used in communication systems. In addition to transmitting voice information for telephone services, information with both speech and data content is also being transmitted for several applications, such as video conferencing.

[0003] To ensure an optimum transmission speed or transmission bandwidth, the information is compressed before transmission. The speech part can be compressed with some loss. The algorithm used for this can however not be used for the data part of the information as this would lead to unwanted loss of information.

[0004] Furthermore, it is preferable to transmit the parts using different transport protocols. Accordingly, the information to be transmitted is divided into speech and data parts and transmitted separately.

[0005]FIG. 3 is a schematic diagram showing a device for transmitting information in a traditional communication system. The information from a sender 10 for a receiver 40 is first divided by an interface unit 20 into a speech part and a data part and then transmitted to a second interface unit 30. The separate transmission of the parts is controlled by a control message (arrow with dotted line). The arrow represents bi-directional data traffic as receipt is usually confirmed by a control message.

[0006] A traditional transmission operation in interface units 20 and 30 is shown in the left and right halves of FIG. 4. The first interface unit 20 receives information that comprises a speech part and data part from the sender 10 to be transmitted to the receiver 40. In the first stage (dividing), the information is divided into its component parts. In the second stage (coding), the speech and data parts are compressed and formatted according to the protocols used. The speech and data parts are transmitted to two different ports on the second interface unit 30.

[0007] So that the second interface unit 30 recognizes the identity of the parts, an appropriate control message is sent at a higher protocol level. In this example, a H.323 message is used to inform the second interface unit about the two ports. H.323 is a standard that defines components, procedures and protocols for audio-visual communication over packet-switched networks.

[0008] In a first stage (decoding), the second interface unit 30 interprets the received H.323 message and allocates the parts accordingly. In a second stage (combining), the original information formed from the parts is combined so that it can be forwarded to the receiver 40.

[0009] Since a connection has to be set up using the control message before transmission can occur, there is a time delay caused by transmitting, answering and processing the control message.

[0010] The object of the invention is to provide a method and a device that avoids the time delay attributable to the control message.

[0011] This object is achieved in that a method according to claim 1 or a device according to claim 11 is provided. The subclaims describe the preferred embodiments of the invention.

[0012] According to the present invention in a communications system that uses Internet Protocol (IP)-based transmission of information comprising a speech part and a data part from a first to a second interface unit, the information will be divided into speech and data parts and transmitted using different ports. In the second interface unit, the corresponding transmitted speech and data parts are allocated using dedicated ports. Corresponding information is transmitted to corresponding ports, making an additional control message unnecessary.

[0013] In a preferred embodiment of the method, more than two ports are dedicated as corresponding ports. The interface unit can therefore select the appropriate combination of ports required for the information.

[0014] In a further preferred embodiment of the method, the data part is transmitted using a Transmission Control Protocol (TCP) that guarantees a dedicated sequence of data packets and error correction. It is further preferable to transmit the speech part using a User Datagram Protocol (UDP), since UDP guarantees a higher transmission speed.

[0015] In a further embodiment of the method, the data part contains a combination of types of data, supporting various types of data and applications.

[0016] According to a preferred embodiment of the method, the information is divided into a speech part and a data part in the scope of the first interface unit. This means that the method can be used independently from the interfaces of different applications.

[0017] According to a preferred embodiment of the method, the speech part is compressed with some loss before transmission to achieve a faster transmission.

[0018] According to the present invention, a device in a communications system with two interface units with a plurality of ports realizes the required method.

[0019] The invention will now be described below with reference to the accompanying drawings using preferred embodiments. The drawings show in detail as follows:

[0020]FIG. 1 a schematic diagram of a device according to the present invention in a communications system,

[0021]FIG. 2 a schematic diagram of a method according to the present invention for the first and second interface units from FIG. 1,

[0022]FIG. 3 a schematic diagram of a device in a standard communications system,

[0023]FIG. 4 a schematic diagram of a standard method for the first and second interface units from FIG. 3,

[0024]FIG. 1 shows a device according to the present invention with a sender 10, a receiver 40, a first interface unit 20 and a second interface unit 30. The information to be transmitted from the sender 10 to the receiver 40 is divided into a speech part and a data part using two ports and transmitted from the first interface unit 20 to the second interface unit 30. A first port is assigned for the speech part, a second for the data part.

[0025] The left-hand side of FIG. 2 describes a sample schematic process in the first interface unit 20. In a first stage (dividing), the information received and to be transmitted is divided into a speech part and a data part. Sequences from dual-tone multi-frequency dialing may be used as characterizing features for data parts. In the second stage (coding), the speech part with some loss is compressed, while the data part is compressed without loss using an algorithm. The data part is then transmitted using TCP and the speech part using UDP to two different ports on the second interface unit 30. Ports used for transmitting data are allocated according to a list (definition) that assigns ports either individually, in pairs or in groups to a connection.

[0026] The process in the second interface unit 30 is shown schematically in the right-hand side of FIG. 2. The speech part and the data part of the information are received at 30 different ports. In a first stage (decoding), the parts are decompressed separately and then assigned to one another according to the definition. To forward the information to the receiver 40, in a second stage (combining), the speech part and data part are combined into complete information again.

[0027] As a connection between sender 10 and receiver 40 normally comprises an information stream, that is split into individual data packets at the latest in the Internet Protocol, FIGS. 2 and 4 only show the principle of the method and not a necessary time scale.

[0028] Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are known as IP-based transport protocols. TCP is used for transmitting data, as the connection-oriented transport service TCP guarantees a complete, error-free transmission with dedicated sequence of packets. The connection-free UDP offers a higher speed for transmission as the connection set up, clear down and confirmation is not needed during communication. With both UDP and TCP, the transmitted packets are assigned to the source and target applications via the ports.

[0029] The data part can comprise graphic data, other types of data or a combination of graphic data and other types of data. This means that the data part may be significantly greater than the speech part. In this case or if an application makes greater demands on the transmission speed of the data part, then it may be sensible to use three ports for the data part and one port for the speech part. For this type of use, the combination of ports must be planned into the definition.

[0030] The sender 10 and the receiver 40 may be video telephones or computers with microphones. The interface units 20 and 30 may be gateways or an agent in a communications system, for which information streams occur with information of a connection, mixed or unforeseeable with speech and data parts. The information may be at the interface unit or already divided into its component parts. The interface units can also be end units, if the end units are a plurality of interfaces. 

1. Method for Internet Protocol (IP)-based transmission of information comprising a speech part and a data part in a communications system between interface units with a plurality of ports with the following stages: Transmitting information from a first to a second interface unit, divided into speech and data parts using different ports; Allocating corresponding transmitted speech and data parts of the information in the second interface unit; characterized in that: the allocation takes place using dedicated ports for corresponding speech and data parts.
 2. Method according to claim 1 characterized in that more than 2 ports are agreed as corresponding.
 3. Method according to claim 1 or 2 characterized in that the data part is transmitted using the Transmission Control Protocol (TCP).
 4. Method according to one of the claims 1 to 3 characterized in that the speech part is transmitted using the User Data Protocol (UDP).
 5. Method according to one of the claims 1 to 4 characterized in that the data part contains graphics data.
 6. Method according to one of the claims 1 to 5 characterized in that the data part contains a combination of types of data.
 7. Method according to one of the claims 1 to 6, that information is divided into speech and data parts in the area of the first interface unit.
 8. Method according to one of the claims 1 to 7 which combines the parts in the area of the second interface unit.
 9. Method according to one of the claims 1 to 8 that compresses the speech part with some loss before transmission.
 10. Method according to one of the claims 1 to 9 that compresses the data part before transmission.
 11. Device in a communications system with two interface units with a plurality of ports that realizes one of the methods according to the claims 1 to
 10. 